Tracheostomy tubes are widely used to supply air to the lungs of unconscious patients such as injured persons and patients undergoing surgery.
In order for the tracheostomy tube to function as intended it must be properly applied to the trachea so that air can be directed through the tube and into the trachea. However, proper insertion of the tube represents a very difficult task and it is possible during the insertion procedure to miss the surgically prepared opening in the trachea and misguide the tracheostomy tube device into the surrounding tissue. Failure to properly insert the tracheal tube can cause serious problems and incur dangerous consequences for the patient. Otolaryngologists, Thoracic Surgeons, General Surgeons and other clinical professionals may experience difficulties in performing intubation procedures. To assist the physician, a variety of guides such as stylets or obturators are available to clinicians to guide and to assist the placement of such tubes in the patient's trachea.
The obturators are used to guide metal or polymeric tracheostomy tubes such as described, for example, in U.S. Pat. Nos. 3,088,466 and 3,659,612 to Shiley et al. The characteristic common feature of these tubes is a constant radius design of the cannula portion. A constant radius cannula is defined herein as a cannula having a continuous curvature between its proximal and distal ends.
It is important in the intubation procedure that the obturator be not only easily insertable into the cannula, but also easily and safely removable after the intubating has been completed.
The removal of the obturator used with tracheostomy tubes having constant radius cannula does not present significant problems as the obturator can be easily pulled along the radius of curvature for easy frictionless removal.
However, many flexible tracheostomy tubes used nowadays are designed to include a non-constant radius cannula. Typically such a tracheostomy tube has at least two substantially straight cannula sections and a curved section located therebetween. The arc of the curve may be designed as forming a right angle or approaching a right angle. The straight sections may be of considerable length. The withdrawal of the obturator from the non-constant radius cannula presents a more difficult task.
U.S. Pat. No. 4,471,776 to Cox describes an example of a tracheostomy tube including an obturator with an adjustable shape. This obturator includes a mealable shaft which allows for the obturator placed inside the tube to be bent together with the tube to a desired curved configuration. However, it is difficult to remove the obturator from the tracheostomy tube since the forces which maintain the curved geometry of the tube and the obturator have to be overcome.
Other types of flexible guiding devices available on the market are so-called "steerable" wire guide devices which bend to a selected fixed constant curvature. Such guiding stylets inserted into the catheter/cannula are designed to impact the curvature to the catheter/cannula. The wire-type guiding devices are most commonly employed with medical devices having an extremely long length as compared to their diameter which is usually very small. The spring-like functions of such small diameter guidewires would be difficult to overcome when such mechanisms are applied to the typical geometry of a tracheostomy or endotracheal tube.
For accomplishing a proper intubation, it is very important that the cannula maintains its shape and does not become occluded or distorted, such that an airway passway is maintained clear through the intubated cannula during and after the intubation procedure.
There is a significant need in the art for an obturator suitable for use with tracheostomy tubes, particularly those including a non-constant radius cannula, which would eliminate disadvantages of the prior art. There does not exist a highly flexible, plastic, single-piece, easily insertable and safely removable guiding device especially suitable for tracheostomy tubes having non-constant radius cannula.
There is a need for an obturator which would substantially prevent tracheostomy tube occlusion or collapse during the intubation and additional distortion of the device once the tube is in place in the trachea, increasing the patient's safety and comfort.